What device is inside a TO-3 can marked APS100 ?

[GrimJosef]

I've come across a small number of reclaimed TO-3 devices and have managed to identify all but one of them. I wonder if anyone knows what it is ?

I only have access to a relatively poor quality camera at the moment, so apologies for the image quality, but the attached pics should show that the can style is what I'd call 'traditional', which is to say the cover is a plain top-hat shape with the attachment seam to the mounting plate clearly visible. The text is equally plain, reading, in three centred rows, SM APS100 3281.

A simple diode test, using a DMM, suggests this might be an NPN junction transistor, with no conductivity from collector to emitter, a little over 0.4V (forward drop) across the base-collector junction and 0.5V or so across base-emitter.

I wonder if it might be an in-house branded TV line output transistor ? The collection does include an R2010 and an R2540.

Cheers,

GJ

[Restoration73]

Both thyristors and triacs were made in TO-3 cases and once you have identified anode
cathode and gate (or MT1, MT2, gate) the test is to use an Avo on low ohms range
across anode and cathode - should show o/c. When gate is made positive i.e. touch on
black Avo lead, the resistance will drop say, 10 to 50 ohms.

[GrimJosef]

Regulators and FETs were made in TO-3 cases too. Among the devices I have are an MC7905CK, a UA78H12SC, an LAS1524 and an IRF150CE. So the can I have could contain almost anything, I suspect. I was hoping I might find someone who'd recognise the number. If I knew what it was equivalent to then that would let me hunt for a datasheet.

Cheers,

GJ

[kalee20]

Originally Posted by GrimJosef

Regulators and FETs were made in TO-3 cases too. ... So the can I have could contain almost anything, I suspect.

And even double-diodes for full-wave rectification with a centre-tapped transformer secondary.

Checking with an Avo, you might think at first you had a bipolar transistor (with the rather unusual connection of base to can), but you'd find it had absolutely zero gain.